Daifuku is a sort of rice cake but it's got stuff inside and my favorite one has a whole strawberry in it. How sweet. There are actually lots of places your can find strawberry daifuku but this one from Yamato-ya (大和や) near Keio Inokashira line Kugayama station is unprecedented.
Fresh veggies from 加津佐 (Kazusa)! Kazusa is the southernmost part of Minamishimabara city in Nagasaki. It is most famous for potatoes and onions, and it was my home for 2 years. That place will always be special to me!
When picnic in the park, I often make my own sandwich kit. It's handy and you can make delicious sandwiches everywhere. Freshly baked bread is the key. Fortunately in Tokyo, there is a local bakery in almost any towns and I can easily find freshly baked breads. Grab a few slices of bread, tomato, lettuce, pastrami and anything you like to sandwich with, and pack them with butter, mayonnaise, ketchup, or any sauces you like. don't forget to take disposable knives and plates. As cherry blossom is in full bloom in the park, a piece of my own sandwich adds a relish to the picnic.
Not exactly 15 minutes to be ready to eat but basically all you have to do is mixing up all the ingredients, fill up the cups, and place them in Oven. Depending on the ability of your oven it would take an hour or so but I still made it with my not-so-great microwave oven so you should be fine with your oven.
People say Tokyo is a dead city for good Mexican but I always enjoy home made tacos as it's easy and fun to make. Preferably choose hard taco shells, get nice pieces of beef in the nearest super market and mince it up with our new food processor, or just get a package of mince meat. Fry the mince with beans and any vegetable you like. Fill up the shell with the fried meat and top with grated cheese and taco sauce which you can find in any super market.